
def dot(a,b):
    (sum)=0;
c=zip(a,b)
for item in c:
    sum+=item[0]*item[1]
    return sum
    def mo(a):
        sum=0
        for i in a:
            sum+=i*i
            return sum**0.5
            import math
            def angle(a,b):
                ji=dot(a,b)
                amo=mo(a)
                bmo=mo(b)
                cos=ji/(amo*bmo)
                hudu=math.acos(cos)
                jiaodu=hudu*180/math.pi
                return jiaodu